Driver circuit for reference voltage should reflects the input reference voltage to the output, while driving it with significantly lower output impedance. The conventional circuit for driving reference voltage uses high power and typically, uses amplifier which is implemented as class A or class AB or class B amplifier.
In battery operated, or in energy harvesting applications, there is a need to minimize the power consumption. It is necessary to provide circuit that consume power that is close to their minimum theoretical power. Such circuits should consume power only when they need to perform a change in their outputs.
There are low power applications that require reference voltage. An example is a driver for LCD display that have one or two reference voltage for driving the segments in the display. Such application might be operated by batteries, such as in water consumption monitors. In such application, the current load is low, but switching noise might shift the output beyond the desired range.